An integrated multi-sensor electronic nose system

Abstract

The application relates to the technical field of gas detection, and discloses an integrated multi-sensor electronic nose system which comprises an air inlet unit, a reaction unit and an air outlet unit; the air inlet unit comprises a first two-position three-way valve, a second two-position three-way valve and a third two-position three-way valve, the first two-position three-way valve is connected with a baseline adjustment channel, a sampling channel and the second two-position three-way valve, the third two-position three-way valve is connected with an enrichment channel and the second two-position three-way valve, the second two-position three-way valve and the third two-position three-way valve are connected with the reaction unit; the reaction unit comprises first, second and third reaction chambers which are arranged side by side, the first, second and third reaction chambers are arranged side by side, and the outlets of the reaction unit are all connected with the air outlet unit; the air outlet unit comprises a fourth two-position three-way valve, and the fourth two-position three-way valve is connected with a first air outlet and a second air outlet. The application integrates multiple sensors and reaction chambers, and improves the accuracy and reliability of gas detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas detection, in particular to an integrated multi-sensor electronic nose system. BACKGROUND

[0002] In the field of gas detection, traditional electronic nose systems usually rely on a single type of sensor to detect and analyze gas components. However, due to the different response characteristics of different gas components to sensors, a single sensor often has difficulty in accurately distinguishing and identifying complex gas mixtures, reducing the accuracy and reliability of detection. In order to overcome these limitations, the present application proposes an integrated multi-sensor electronic nose system. The system improves the accuracy and reliability of gas detection by integrating multiple different types of sensors. SUMMARY

[0003] The purpose of the present application is to provide an integrated multi-sensor electronic nose system to solve the above problems.

[0004] The present application provides an integrated multi-sensor electronic nose system, comprising: an air inlet unit, a reaction unit and an air outlet unit;

[0005] The air inlet unit comprises a first two-position three-way valve, a second two-position three-way valve and a third two-position three-way valve, the A port of the first two-position three-way valve is connected with a baseline adjustment channel, the B port of the first two-position three-way valve is connected with a sampling channel, the C port of the first two-position three-way valve is connected with the B port of the second two-position three-way valve, the A port of the third two-position three-way valve is connected with an enrichment channel, the C port of the third two-position three-way valve is connected with the C port of the second two-position three-way valve, the A port of the second two-position three-way valve is connected with the reaction unit, and the B port of the third two-position three-way valve is connected with the reaction unit.

[0006] The reaction unit comprises a first reaction chamber, a second reaction chamber and a third reaction chamber, the first reaction chamber, the second reaction chamber and the third reaction chamber are arranged side by side, and the outlets of the first reaction chamber, the second reaction chamber and the third reaction chamber are connected with the air outlet unit.

[0007] The air outlet unit comprises a fourth two-position three-way valve, the C port of the fourth two-position three-way valve is connected with the outlet of the reaction unit, the B port of the fourth two-position three-way valve is connected with a first air outlet, and the A port of the fourth two-position three-way valve is connected with a second air outlet.

[0008] Preferably, the air inlet unit further comprises a first vacuum pump and an electronic flowmeter.

[0009] The inlet of the first vacuum pump is connected with the A port of the second two-position three-way valve, the inlet of the first vacuum pump is connected with the B port of the third two-position three-way valve, the outlet of the first vacuum pump is connected with the electronic flow meter, and the electronic flow meter is connected with the reaction unit.

[0010] Preferably, the reaction unit comprises a first two-position two-way valve, a second two-position two-way valve, a third two-position two-way valve and a fourth two-position two-way valve.

[0011] The inlet of the first two-position two-way valve is connected with the electronic flow meter, and the outlet of the first two-position two-way valve is connected with the inlets of the first reaction chamber, the second reaction chamber and the third reaction chamber.

[0012] The inlet of the second two-position two-way valve is connected with the outlet of the first reaction chamber, and the outlet of the second two-position two-way valve is connected with the exhaust unit.

[0013] The inlet of the third two-position two-way valve is connected with the outlet of the second reaction chamber, and the outlet of the third two-position two-way valve is connected with the exhaust unit.

[0014] The inlet of the fourth two-position two-way valve is connected with the outlet of the third reaction chamber, and the outlet of the fourth two-position two-way valve is connected with the exhaust unit.

[0015] Preferably, the exhaust unit further comprises a second vacuum pump and a manual flow meter.

[0016] The inlet of the second vacuum pump is connected with the outlet of the reaction unit, the outlet of the second vacuum pump is connected with the manual flow meter, and the outlet of the manual flow meter is connected with the C port of the fourth two-position three-way valve.

[0017] Preferably, the first two-position three-way valve, the second two-position three-way valve, the third two-position three-way valve and the fourth two-position three-way valve are all solenoid valves, and when the first two-position three-way valve, the second two-position three-way valve, the third two-position three-way valve and the fourth two-position three-way valve lose power, the AC port is turned on, and when the first two-position three-way valve, the second two-position three-way valve, the third two-position three-way valve and the fourth two-position three-way valve are powered on, the BC port is turned on.

[0018] Preferably, the first reaction chamber is provided with:

[0019] An oxygen sensor for detecting the oxygen concentration in the first reaction chamber.

[0020] A carbon dioxide sensor for detecting the carbon dioxide concentration in the first reaction chamber.

[0021] Preferably, the second reaction chamber is provided with:

[0022] A methane sensor for detecting the methane concentration in the second reaction chamber.

[0023] propane, butane sensor, for detecting the concentration of propane, butane in the second reaction chamber;

[0024] hydrogen sensor, for detecting the concentration of hydrogen in the second reaction chamber;

[0025] carbon monoxide sensor, for detecting the concentration of carbon monoxide in the second reaction chamber;

[0026] composite sensor, for detecting the concentration of alkane gas in the second reaction chamber.

[0027] Preferably, a plurality of PID sensors are arranged in the third reaction chamber, and the PID sensors are used for detecting ethanol, amines, hydrogen sulfide, aldehydes, lipids and ketone compounds.

[0028] Preferably, the electronic nose system comprises a baseline adjustment mode, a sampling mode and an enrichment mode;

[0029] In the baseline adjustment mode, the electronic flowmeter is adjusted to an initial value, the baseline adjustment channel is connected with a standard gas, the second two-position three-way valve, the third two-position three-way valve and the first two-position two-way valve are powered on, the first vacuum pump is powered on to draw the standard gas through the electronic flowmeter into the first reaction chamber, the second reaction chamber and the third reaction chamber; at the same time, the second two-position two-way valve, the third two-position two-way valve and the fourth two-position two-way valve are powered on, and the second vacuum pump is powered on to draw the mixed gas of the standard gas and air in the reaction unit out through the second exhaust port until the sensor values in the first reaction chamber, the second reaction chamber and the third reaction chamber are stable.

[0030] Preferably, in the sampling mode, after the baseline adjustment mode is completed, the second two-position three-way valve, the third two-position three-way valve, the first two-position two-way valve and the first vacuum pump are powered off; the second vacuum pump is powered on to draw the standard gas in the reaction unit out;

[0031] The first two-position three-way valve, the second two-position three-way valve, the third two-position three-way valve and the first two-position two-way valve are powered on, the first vacuum pump is powered on to draw the sampling gas into the first reaction chamber, the second reaction chamber and the third reaction chamber, the second two-position two-way valve, the third two-position two-way valve, the fourth two-position two-way valve and the fourth two-position three-way valve are powered on, and the second vacuum pump is powered on to draw the mixed gas of the standard gas and the sampling gas in the reaction unit out through the first exhaust port until the sensor values in the first reaction chamber, the second reaction chamber and the third reaction chamber are stable.

[0032] Compared with the prior art, the present application has the beneficial effects that, by integrating a plurality of different types of sensors, the present application can simultaneously detect a plurality of gas components, and through data fusion technology, the detection results are comprehensively analyzed, thereby improving the accuracy and reliability of gas detection. In addition, the system also has a self-calibration function, which can adapt to environmental changes and ensure long-term stable operation.

[0033] The present application can process multiple gas samples by setting different reaction chambers and channels, and is suitable for different application scenarios. For example, the baseline adjustment channel can be used to calibrate the sensor, the sampling channel is used to introduce the gas to be measured, and the enrichment channel can be used to improve the detection sensitivity of low concentration gas. The use of two three-way valves increases the flexibility of the system, allowing quick switching between different operating modes. For example, different gas inlet or exhaust paths can be selected by changing the state of the valve to adapt to different experimental needs. The first, second and third reaction chambers arranged side by side can improve the processing capacity of the system, so that multiple samples can be analyzed at the same time, thereby improving the overall analysis efficiency. The outlet of each reaction chamber is connected with the exhaust unit, and the fourth two three-way valve in the exhaust unit can accurately control the exhaust path, ensuring the controllability and repeatability of gas flow, which is crucial to ensure the accuracy of experimental results. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only a part of the embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0035] Figure 1 is a structural schematic diagram of an integrated multi-sensor electronic nose system of the present application.

[0036] In the figure, 1 is a baseline adjustment channel; 2 is a sampling channel; 3 is an enrichment channel; 4 is a first two three-way valve; 5 is a second two three-way valve; 6 is a third two three-way valve; 7 is a fourth two three-way valve; 8 is a first reaction chamber; 9 is a second reaction chamber; 10 is a third reaction chamber; 11 is a first vacuum pump; 12 is an electronic flow meter; 13 is a first two two-way valve; 14 is a second two two-way valve; 15 is a third two two-way valve; 16 is a fourth two two-way valve; 17 is a second vacuum pump; 18 is a manual flow meter; 19 is a first exhaust port; 20 is a second exhaust port. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0038] In the description of the present application, it needs to be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0039] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0040] In the description of the present application, it needs to be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0041] As shown in Figure 1 The present application provides an integrated multi-sensor electronic nose system, comprising: an air inlet unit, a reaction unit and an air outlet unit;

[0042] The air inlet unit comprises a first two-position three-way valve 4, a second two-position three-way valve 5 and a third two-position three-way valve 6, the A port of the first two-position three-way valve 4 is connected with the baseline adjustment channel 1, the B port of the first two-position three-way valve 4 is connected with the sampling channel 2, the C port of the first two-position three-way valve 4 is connected with the B port of the second two-position three-way valve 5, the A port of the third two-position three-way valve 6 is connected with the enrichment channel 3, the C port of the third two-position three-way valve 6 is connected with the C port of the second two-position three-way valve 5, the A port of the second two-position three-way valve 5 is connected with the reaction unit, and the B port of the third two-position three-way valve 6 is connected with the reaction unit;

[0043] The reaction unit comprises a first reaction chamber 8, a second reaction chamber 9 and a third reaction chamber 10, the first reaction chamber 8, the second reaction chamber 9 and the third reaction chamber 10 are arranged side by side, and the outlets of the first reaction chamber 8, the second reaction chamber 9 and the third reaction chamber 10 are all connected with the air outlet unit;

[0044] The exhaust unit comprises a fourth two-position three-way valve 7, the C port of the fourth two-position three-way valve 7 is connected with the outlet of the reaction unit, the B port of the fourth two-position three-way valve 7 is connected with the first exhaust port 19, and the A port of the fourth two-position three-way valve 7 is connected with the second exhaust port 20.

[0045] In some embodiments of the present application, the gas inlet unit further comprises a first vacuum pump 11 and an electronic flow meter 12; the inlet of the first vacuum pump 11 is connected with the A port of the second two-position three-way valve 5, the inlet of the first vacuum pump 11 is connected with the B port of the third two-position three-way valve 6, the outlet of the first vacuum pump 11 is connected with the electronic flow meter 12, and the electronic flow meter 12 is connected with the reaction unit.

[0046] In this embodiment, whether it is a standard gas, a sampling gas or other gas to be collected, the first vacuum pump 11 is needed to extract, and then the gas enters the reaction chamber through the electronic flow meter 12.

[0047] The use of the electronic flow meter 12 ensures accurate control of the gas flow, which is crucial for the accuracy and repeatability of chemical reactions in the reaction unit. By precisely measuring and adjusting the flow of gas, it can ensure uniform distribution of gas in the reaction chamber, thereby improving the sensitivity and accuracy of detection. In addition, the real-time monitoring function of the electronic flow meter 12 can also help users to discover and adjust any abnormal flow in the system in a timely manner, ensuring the stable operation of the entire electronic nose system. In some advanced applications, the electronic flow meter 12 can also be integrated with the control system to achieve automatic flow adjustment, further improving the intelligent level of the system.

[0048] In some embodiments of the present application, the reaction unit comprises a first two-position two-way valve 13, a second two-position two-way valve 14, a third two-position two-way valve 15 and a fourth two-position two-way valve 16; the inlet of the first two-position two-way valve 13 is connected with the electronic flow meter 12, the outlet of the first two-position two-way valve 13 is connected with the inlets of the first reaction chamber 8, the second reaction chamber 9 and the third reaction chamber 10; the inlet of the second two-position two-way valve 14 is connected with the outlet of the first reaction chamber 8, and the outlet of the second two-position two-way valve 14 is connected with the exhaust unit; the inlet of the third two-position two-way valve 15 is connected with the outlet of the second reaction chamber 9, and the outlet of the third two-position two-way valve 15 is connected with the exhaust unit; the inlet of the fourth two-position two-way valve 16 is connected with the outlet of the third reaction chamber 10, and the outlet of the fourth two-position two-way valve 16 is connected with the exhaust unit.

[0049] In this embodiment, the first two-position two-way valve 13, the second two-position two-way valve 14, the third two-position two-way valve 15 and the fourth two-position two-way valve 16 are all solenoid valves, the first two-position two-way valve 13 is a total control valve, which is arranged on the total gas inlet pipeline and is used for controlling the gas entering the reaction chamber. The second two-position two-way valve 14, the third two-position two-way valve 15 and the fourth two-position two-way valve 16 are branch control valves, which are arranged on the branch pipelines of each reaction chamber and are used for controlling the gas flow of each branch pipeline.

[0050] In some embodiments of the present application, the exhaust unit further comprises a second vacuum pump 17 and a manual flow meter 18; the inlet of the second vacuum pump 17 is connected with the outlet of the reaction unit, the outlet of the second vacuum pump 17 is connected with the manual flow meter 18, and the outlet of the manual flow meter 18 is connected with the C port of the fourth two-way three-way valve 7.

[0051] In this embodiment, when the sensor in the reaction chamber completes detection, the second vacuum pump 17 is started to extract the gas in the reaction chamber, which is then discharged through the manual flow meter 18. The speed of gas discharge can be controlled by adjusting the manual flow meter 18.

[0052] In some embodiments of the present application, the first two-way three-way valve 4, the second two-way three-way valve 5, the third two-way three-way valve 6 and the fourth two-way three-way valve 7 are all solenoid valves. When the first two-way three-way valve 4, the second two-way three-way valve 5, the third two-way three-way valve 6 and the fourth two-way three-way valve 7 lose power, the AC port is turned on. When the first two-way three-way valve 4, the second two-way three-way valve 5, the third two-way three-way valve 6 and the fourth two-way three-way valve 7 are powered on, the BC port is turned on.

[0053] In this embodiment, the first two-way three-way valve 4, the second two-way three-way valve 5, the third two-way three-way valve 6 and the fourth two-way three-way valve 7 all adopt electromagnetic control principle. In the power-off state, i.e. when they do not receive current, the AC port will be in the on state, allowing gas to pass through. Conversely, when these solenoid valves are powered on, i.e. receive current, the BC port will be turned on, and the gas will flow through the BC port. This design enables the system to switch the flow direction of the fluid by controlling the on-off of the current, achieving precise control of the fluid path.

[0054] In some embodiments of the present application, the first reaction chamber 8 is provided with: an oxygen sensor for detecting the oxygen concentration in the first reaction chamber 8; a carbon dioxide sensor for detecting the carbon dioxide concentration in the first reaction chamber 8.

[0055] In some embodiments of the present application, the second reaction chamber 9 is provided with: a methane sensor for detecting the methane concentration in the second reaction chamber 9; a propane, butane sensor for detecting the propane, butane concentration in the second reaction chamber 9; a hydrogen sensor for detecting the hydrogen concentration in the second reaction chamber 9; a carbon monoxide sensor for detecting the carbon monoxide concentration in the second reaction chamber 9; and a composite sensor for detecting the alkane gas concentration in the second reaction chamber 9.

[0056] In the present embodiment, the sensors provided in the second reaction chamber 9 can be: sensor MQ-6 for detecting propane, butane, liquefied gas. Sensor MQ-2 for detecting methane (CH4) exclusively. Sensor MQ-8 for detecting methane, isobutane, various alkane gases. Sensor MQ-5 for detecting methane, butane and other alkane gases. Sensor MQ-6 for detecting liquefied gas, propane, butane again. Sensor MQ-8 for detecting hydrogen and carbon monoxide.

[0057] In some embodiments of the present application, a plurality of PID sensors are provided in the third reaction chamber 10, and the PID sensors are used for detecting ethanol, amines, hydrogen sulfide, aldehydes, lipids and ketone compounds.

[0058] In the present embodiment, the sensors provided in the third reaction chamber 10 can be: PID (photoionization) sensors are generally used for detecting ethanol, lipids, alcohols and other organic volatile gases. MQ series semiconductor sensors such as MQ-2 and MQ-136 are generally used for detecting hydrogen sulfide (H2S), amine compounds and volatile organic compounds (VOCs). MQ-136 or MQ-4 type sensors are commonly used for detecting hydrogen sulfide (H2S) exclusively. MQ-135 or MQ-136 type sensors can be used for detecting ammonia, hydrogen sulfide and other volatile organic compounds. MQ series sensors are also commonly used for detecting ammonia, hydrogen sulfide and other volatile organic compounds in the air. Electrochemical sensors are generally used for detecting aldehydes, ketones and other organic solvent gases. Electrochemical sensors are mainly used for detecting formaldehyde.

[0059] In some embodiments of the present application, the electronic nose system includes a baseline adjustment mode, a sampling mode and an enrichment mode;

[0060] The baseline adjustment mode is: adjusting the electronic flowmeter 12 to an initial value, connecting the baseline adjustment channel 1 with the standard gas, energizing the second two-position three-way valve 5, the third two-position three-way valve 6 and the first two-position two-way valve 13, and energizing the first vacuum pump 11 to draw the standard gas through the electronic flowmeter 12 into the first reaction chamber 8, the second reaction chamber 9 and the third reaction chamber 10; at the same time, energizing the second two-position two-way valve 14, the third two-position two-way valve 15 and the fourth two-position two-way valve 16, and energizing the second vacuum pump 17 to draw the mixed gas of the standard gas and air in the reaction unit out through the second exhaust port 20 until the sensor values in the first reaction chamber 8, the second reaction chamber 9 and the third reaction chamber 10 are stable.

[0061] In this embodiment, the second vacuum pump 17 discharges the gas in the three reaction chambers, and the gas slowly flows out through the second exhaust port 20 at a speed that is first fast and then slow by manually adjusting the valve. In this process, the values collected by the sensors of the three reaction chambers are observed, and when the baseline adjustment is stable, the sensor baseline can be calibrated at this time.

[0062] In some embodiments of the present application, the sampling mode is as follows: after the completion of the baseline adjustment mode, the second two-position three-way valve 5, the third two-position three-way valve 6, the first two-position two-way valve 13 and the first vacuum pump 11 are powered off; the second vacuum pump 17 is powered on to discharge the standard gas in the reaction unit; the first two-position three-way valve 4, the second two-position three-way valve 5, the third two-position three-way valve 6 and the first two-position two-way valve 13 are powered on, and the first vacuum pump 11 is powered on to extract the sampling gas into the first reaction chamber 8, the second reaction chamber 9 and the third reaction chamber 10; the second two-position two-way valve 14, the third two-position two-way valve 15, the fourth two-position two-way valve 16 and the fourth two-position three-way valve 7 are powered on, and the second vacuum pump 17 is powered on to extract the mixed gas of the standard gas and the sampling gas in the reaction unit through the first exhaust port 19, until the sensor values in the first reaction chamber 8, the second reaction chamber 9 and the third reaction chamber 10 are stable.

[0063] In this embodiment, when the second vacuum pump 17 is powered on to discharge the standard gas in the reaction unit, the flow control of the manual flowmeter 18 is adjusted to slowly discharge the standard gas in the three reaction chambers, thereby reducing the concentration of the standard gas in the gas chamber and reducing the gas pressure when the sampling gas enters the gas chamber. After the concentration of the gas chamber is reduced (the threshold value needs to be adjusted by actual experiment), the sampling channel 2 starts to intake gas, and the sampling gas quickly enters the gas chamber due to the pressure difference. After the sampling gas basically fills the gas chamber, the manual flowmeter 18 is adjusted to overflow part of the sampling gas and the original standard gas in the gas chamber. At this time, the fourth two-position three-way valve 7 is turned on, and the gas flows out from the first exhaust port 19. After the sampling gas fills the reaction chamber, all solenoid valves and pumps are powered off, and the sensor analyzes and reads the stable reading of the gas. If multiple measurements are required, the above sampling process is repeated.

[0064] The enrichment mode is as follows: the first two-position three-way valve 4 and the second two-position three-way valve 5 are powered off, the third two-position three-way valve 6 is powered on, the first vacuum pump 11 and the first two-position two-way valve 13 are powered on, the enrichment gas enters the reaction chamber through the enrichment channel, the second two-position two-way valve 14, the third two-position two-way valve 15 and the fourth two-position two-way valve 16 are powered on, and the second vacuum pump 17 is powered on to discharge the mixed gas of the enrichment gas and other gases in the reaction chamber, until the reaction chamber is filled with the enrichment gas, and the second two-position two-way valve 14, the third two-position two-way valve 15 and the fourth two-position two-way valve 16 are closed.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An integrated multi-sensor electronic nose system, characterized in that, include: Intake unit, reaction unit, and exhaust unit; The intake unit includes a first two-position three-way valve, a second two-position three-way valve, and a third two-position three-way valve. Port A of the first two-position three-way valve is connected to the baseline adjustment channel, port B of the first two-position three-way valve is connected to the sampling channel, port C of the first two-position three-way valve is connected to port B of the second two-position three-way valve, port A of the third two-position three-way valve is connected to the enrichment channel, port C of the third two-position three-way valve is connected to port C of the second two-position three-way valve, port A of the second two-position three-way valve is connected to the reaction unit, and port B of the third two-position three-way valve is connected to the reaction unit. The reaction unit includes a first reaction chamber, a second reaction chamber, and a third reaction chamber, which are arranged side by side, and the outlets of the first reaction chamber, the second reaction chamber, and the third reaction chamber are all connected to an exhaust unit. The exhaust unit includes a fourth two-position three-way valve, the C port of which is connected to the outlet of the reaction unit, the B port of which is connected to the first exhaust port, and the A port of which is connected to the second exhaust port. The electronic nose system includes a baseline adjustment mode, a sampling mode, and an enrichment mode; The baseline adjustment mode is as follows: the electronic flow meter is adjusted to the initial value, the baseline adjustment channel is connected to the standard gas, the second two-position three-way valve, the third two-position three-way valve, and the first two-position two-way valve are energized, and the first vacuum pump is energized to draw the standard gas through the electronic flow meter into the first reaction chamber, the second reaction chamber, and the third reaction chamber; at the same time, the second two-position two-way valve, the third two-position two-way valve, and the fourth two-position two-way valve are energized, and the second vacuum pump is energized to draw the mixture of standard gas and air in the reaction unit and discharge it through the second exhaust port until the sensor values ​​in the first reaction chamber, the second reaction chamber, and the third reaction chamber stabilize. The sampling mode is as follows: after the baseline adjustment mode is completed, the second two-position three-way valve, the third two-position three-way valve, the first two-position two-way valve and the first vacuum pump are de-energized; the second vacuum pump is energized to extract the standard gas in the reaction unit. When the first two-position three-way valve, the second two-position three-way valve, the third two-position three-way valve, and the first two-position two-way valve are energized, the first vacuum pump is energized to draw the sampling gas into the first reaction chamber, the second reaction chamber, and the third reaction chamber. When the second two-position two-way valve, the third two-position two-way valve, the fourth two-position two-way valve, and the fourth two-position three-way valve are energized, the second vacuum pump is energized to draw the mixture of standard gas and sampling gas in the reaction unit and discharge it through the first exhaust port until the sensor values ​​in the first reaction chamber, the second reaction chamber, and the third reaction chamber stabilize.

2. The integrated multi-sensor electronic nose system according to claim 1, characterized in that, The air intake unit also includes a first vacuum pump and an electronic flow meter; The inlet of the first vacuum pump is connected to port A of the second two-position three-way valve, the inlet of the first vacuum pump is connected to port B of the third two-position three-way valve, the outlet of the first vacuum pump is connected to the electronic flow meter, and the electronic flow meter is connected to the reaction unit.

3. The integrated multi-sensor electronic nose system according to claim 2, characterized in that, The reaction unit includes a first two-position two-way valve, a second two-position two-way valve, a third two-position two-way valve, and a fourth two-position two-way valve; The inlet of the first two-position two-way valve is connected to the electronic flow meter, and the outlet of the first two-position two-way valve is connected to the inlets of the first reaction chamber, the second reaction chamber, and the third reaction chamber. The inlet of the second two-position two-way valve is connected to the outlet of the first reaction chamber, and the outlet of the second two-position two-way valve is connected to the exhaust unit. The inlet of the third two-position two-way valve is connected to the outlet of the second reaction chamber, and the outlet of the third two-position two-way valve is connected to the exhaust unit; The inlet of the fourth two-position two-way valve is connected to the outlet of the third reaction chamber, and the outlet of the fourth two-position two-way valve is connected to the exhaust unit.

4. The integrated multi-sensor electronic nose system according to claim 1, characterized in that, The exhaust unit also includes a second vacuum pump and a manual flow meter; The inlet of the second vacuum pump is connected to the outlet of the reaction unit, the outlet of the second vacuum pump is connected to the manual flow meter, and the outlet of the manual flow meter is connected to port C of the fourth two-position three-way valve.

5. The integrated multi-sensor electronic nose system according to claim 4, characterized in that, The first two-position three-way valve, the second two-position three-way valve, the third two-position three-way valve, and the fourth two-position three-way valve are all solenoid valves. When the first two-position three-way valve, the second two-position three-way valve, the third two-position three-way valve, and the fourth two-position three-way valve are de-energized, the AC port is open. When the first two-position three-way valve, the second two-position three-way valve, the third two-position three-way valve, and the fourth two-position three-way valve are energized, the BC port is open.

6. The integrated multi-sensor electronic nose system according to claim 5, characterized in that, The first reaction chamber is equipped with: An oxygen sensor is used to detect the oxygen concentration in the first reaction chamber; A carbon dioxide sensor is used to detect the carbon dioxide concentration in the first reaction chamber.

7. The integrated multi-sensor electronic nose system according to claim 6, characterized in that, The second reaction chamber is equipped with: A methane sensor is used to detect the methane concentration in the second reaction chamber; Propane and butane sensors are used to detect the concentrations of propane and butane in the second reaction chamber; A hydrogen sensor is used to detect the hydrogen concentration in the second reaction chamber; A carbon monoxide sensor is used to detect the carbon monoxide concentration in the second reaction chamber; A composite sensor is used to detect the concentration of alkane gas in the second reaction chamber.

8. The integrated multi-sensor electronic nose system according to claim 7, characterized in that, The third reaction chamber is equipped with several PID sensors, which are used to detect ethanol, amines, hydrogen sulfide, aldehydes, lipids and ketones.

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